1. Field of the Invention
The present invention relates to a method for manufacturing an electric motor stator including a resin-molded unit, to an electric motor stator, and to an electric motor.
2. Description of the Related Art
As a method for manufacturing such an electric motor stator, for example, a method described in Japanese Laid-open Patent Publication No. 5-56611 (JP 5-056611 A) has been known. In the method described in JP 5-056611 A, brackets are attached to both ends of a hollow stator core to form a stator, and the stator is installed upright between upper and lower dies. A core material is installed upright from the lower die and is inserted into the insides of the stator core and the brackets. In this state, a resin is injected by pressurization through a resin inlet formed in the lower bracket, and the resin is filled between the stator core and the core material and between the brackets and the core material, to form a resin unit in the stator.
An opening that passes through the brackets in a radial direction may be formed in the brackets of an electric motor stator in order to take out a lead connected to a winding to the outside of the stator. However, when the opening is formed in the brackets, there is a fear that injection of a resin by pressurization results in flowing of the resin from the opening.